I do not understand why they can't continue the premise from the previous film (28 Weeks Later). The US quarantine failed, and the virus spread throughout Europe, starting from France. Rather, they explore an incoherent narrative that confuses the audience.
I get that the first movie was groundbreaking in creating a zombie runner genre, but this third installment went too far in a jumbled idea. The first 30 minutes or so are actually good, so you feel like wanting more of that dynamic. Suddenly, the movie throws out that narrative and moves to a very odd direction. Almost feel like there are too many writers, and they decided to pick a little bit from many different scripts.